buildgcc: defer cleaning up the tree a bit

cleanup() uses BUILDDIRPREFIX, which is set after the
getopt loop.

Change-Id: I8a904781ee4fefc42681d31e94b64008cf03750a
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/4544
Tested-by: build bot (Jenkins)
Reviewed-by: Jonathan A. Kollasch <jakllsch@kollasch.net>
1 file changed